Field of the Invention
The present invention relates to the supply of industrial gas from vaporizers fed with liquefied gas.
Related Art
Many manufacturing operations utilize industrial gases for applications, such as welding, cutting, heating, cooling, curing, inerting, burning, etc. For operations consuming large amounts of industrial gas, it is more economical to store the gas in liquefied form. For these types of operations, the gas is obtained by feeding liquefied gas from a storage tank to an ambient temperature vaporizer where the heat of the ambient atmosphere provides the required latent heat of vaporization. Typically the storage tank has a head space pressure superior to any pressure of any component between the storage tank and the point of use for applications such as cited above. In some cases where the gas pressure required at the point of use is larger than the headspace pressure of the storage tank, then a pressure booster system is installed between the storage tank and the point of use. Typically, the relatively high pressure gas resulting from vaporization is reduced to the pressure required by the point of use consuming that gas. Conventional vaporizers and associated gas distribution equipment used in the industrial gas industry (for gases such as oxygen, nitrogen, argon, carbon dioxide, hydrogen, hydrocarbon fuels), however, do not recover any substantial portion of the useful energy from this pressure reduction process.
Liquid nitrogen-powered vehicles are known that vaporize liquid nitrogen and expand the resultant gaseous nitrogen across a turbine. The nitrogen expanded to ambient pressure and simply vented to the atmosphere. While technically interesting, it exhibits poor energy efficiency in that high amounts of electricity is consumed during compression of air fed to air separation units responsible for producing the liquid nitrogen to be used by the vehicle. Also, the nitrogen exhausted from the vehicle is not utilized in any particular useful way.
Thus, it is an object to recovery any useful energy associated with the pressure reduction of a relatively higher pressure gas, resulting from vaporization at a vaporizer.